HTML5 Canvas gradient appears black -

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i'm trying reproduce following background image in html5 canvas, renders on browser black box. original image made in illustrator , that's i'm getting coordinates (actually used export plug-in).

<html lang="en">  <head>   <meta charset="utf-8" />   <title>index</title>   <script>      function init() {        var canvas = document.getelementbyid("canvas");       var ctx = canvas.getcontext("2d");        draw(ctx);     }      function draw(ctx) {        var gradient;        // layer1/red background bottom       ctx.save();       ctx.beginpath();       ctx.moveto(1036.0, 789.7);       ctx.lineto(12.0, 789.7);       ctx.lineto(12.0, 21.7);       ctx.lineto(1036.0, 21.7);       ctx.lineto(1036.0, 789.7);       ctx.closepath();       ctx.fillstyle = "rgb(235, 10, 10)";       ctx.fill();        // layer1/shadow bottom       ctx.beginpath();       ctx.moveto(1036.0, 788.7);       ctx.lineto(12.0, 788.7);       ctx.lineto(12.0, 20.7);       ctx.lineto(1036.0, 20.7);       ctx.lineto(1036.0, 788.7);       ctx.closepath();       ctx.save();       ctx.transform(3.200, 0.000, 0.000, -4.206, 196.6, -5329.4);       gradient = ctx.createradialgradient(96.7, -1580.0, 0.0, 96.7, -1580.0, 161.7);       gradient.addcolorstop(0.00, "rgb(0, 0, 0)");       gradient.addcolorstop(0.55, "rgb(0, 0, 0)");       gradient.addcolorstop(1.00, "rgb(0, 0, 0)");       ctx.fillstyle = gradient;       ctx.fill();       ctx.restore();       ctx.restore();     }   </script>  </head>  <body onload="init()">    <canvas id="canvas" width="1049" height="792"></canvas>  </body> </html>


edit: realized forgot add alphas in gradient stops, change below solves problem:

      gradient.addcolorstop(0.00, "rgba(0, 0, 0,0)");       gradient.addcolorstop(1.00, "rgba(0, 0, 0, 0.5)");

enter image description here

the main problem gradient stops..

 gradient.addcolorstop(0.00, "rgb(0, 0, 0)");  gradient.addcolorstop(0.55, "rgb(0, 0, 0)");  gradient.addcolorstop(1.00, "rgb(0, 0, 0)");

they black (red 0, green 0, blue 0). changing values ...

gradient.addcolorstop(0.00, "rgb(255, 0, 0)"); gradient.addcolorstop(0.55, "rgb(125, 0, 0)"); gradient.addcolorstop(1.00, "rgb(0, 0, 0)");

gives full red in centre (0) (red 255, green 0, blue 0) half red in middle (.55) (red 125, green 0, blue 0) , no red (black) @ edge (1.00) (red 0, green 0, blue 0)

then have change centre point of gradient.

function init() {    var canvas = document.getelementbyid("canvas");    var ctx = canvas.getcontext("2d");      draw(ctx);  }    function draw(ctx) {    var gradient;      // layer1/red background bottom    ctx.save();    ctx.beginpath();    ctx.moveto(1036.0, 789.7);    ctx.lineto(12.0, 789.7);    ctx.lineto(12.0, 21.7);    ctx.lineto(1036.0, 21.7);    ctx.lineto(1036.0, 789.7);    ctx.closepath();    ctx.fillstyle = "rgb(235, 10, 10)";    ctx.fill();      // layer1/shadow bottom    ctx.beginpath();    ctx.moveto(1036.0, 788.7);    ctx.lineto(12.0, 788.7);    ctx.lineto(12.0, 20.7);    ctx.lineto(1036.0, 20.7);    ctx.lineto(1036.0, 788.7);    ctx.closepath();    ctx.save();    ctx.transform(3.200, 0.000, 0.000, -4.206, 196.6, -5329.4);    gradient = ctx.createradialgradient(96.7, -1380.0, 0.0, 96.7, -1580.0, 261.7);    gradient.addcolorstop(0.00, "rgb(250, 0, 0)");    gradient.addcolorstop(0.55, "rgb(125, 0, 0)");    gradient.addcolorstop(1.00, "rgb(50, 0, 0)");    ctx.fillstyle = gradient;    ctx.fill();    ctx.restore();    ctx.restore();  }
<body onload="init()">    <canvas id="canvas" width="1049" height="792"></canvas>  </body>


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